Interleukin-12 (IL-12) is a heterodimeric cytokine (p70) composed of two subunits (p35 and p40), and plays key roles in immune responses by bridging innate resistance and antigen-specific adaptive immunity. Trinchieri (1993) Immunol Today 14: 335. For example, it promotes type 1 T helper cell (Th1) responses and, hence, cell-mediated immunity. Chan et al. (1991) J Exp Med 173: 869; Seder et al. (1993) Proc Natl Acad Sci USA 90: 10188; Manetti et al. (1993) J Exp Med 177: 1199; and Hsieh et al. (1993) Science 260: 547. Overproduction of IL-12 causes excessive Th1 responses, and may result in inflammatory disorders, such as insulin-dependent diabetes mellitus, multiple sclerosis, rheumatoid arthritis, psoriasis, Crohn""s disease, or sepsis. See, for example, Gately et al. (1998) Annu Rev Immunol. 16: 495; and Abbas et al. (1996) Nature 383: 787. Thus, inhibiting IL-12 overproduction is an approach to treat the just-mentioned diseases. Trembleau et al. (1995) Immmunol. Today 16: 383; and Adorini et al. (1997) Chem. Immunol. 68: 175. For example, overproduction of IL-12 and the resultant excessive Th1 type responses can be suppressed by modulating IL-12 production. A compound that down-regulates IL-12 production can be used for treating inflammatory diseases. Ma et al. (1998) Eur Cytokine Netw 9: 54.
In one aspect, this invention features pyrimidine compounds of formula (I): 
R1 is 
xe2x80x83[referred to hereinafter as NC(RaRb)]; each of R2 and R4 is H; R3 is H, alkyl, aryl, heteroaryl, cyclyl, heterocyclyl, or alkylcarbonyl; R5 is H or alkyl; n is 0, 1, 2, 3, 4, 5, or 6; X is NRc; Y is covalent bond, CH2, C(O), Cxe2x95x90Nxe2x80x94Rc, Cxe2x95x90Nxe2x80x94ORc, Cxe2x95x90Nxe2x80x94SRc, O, S, S(O), S(O2), or NRc; Z is N or CH; one of U and V is N, and the other is CRc; and W is O, S, S(O), S(O2), NRc, or NC(O)Rc; in which each of Ra and Rb, independently, is H, alkyl, aryl, heteroaryl; and Rc is H, alkyl, aryl, heteroaryl, cyclyl, heterocyclyl, or alkylcarbonyl. Note that the left atom shown in any substituted group described above is closest to the pyrimidine ring. Also note that when there are more than one Rc-containing substituted groups in a pyrimidine compound, the Rc moieties can be the same or different.
In some embodiments, one of Ra and Rb is H or alkyl; and the other is 
(e.g. 3-methylphenyl); in which Rd is H, alkyl, or alkoxyl; Re is halogen, CN, hydroxyl, alkyl, aryl, heteroaryl, alkoxyl, aryloxyl, or heteroaryloxyl; and m is 0, 1, 2, 3, or 4.
In other embodiments, X is NH; Y is O; or n is 2.
In still other embodiments, U is N; V is CH; and R3 is heteroaryl (e.g., 1-oxy-pyridin-2-yl). Preferably, X is NH; Y is O; n is 2; and one of Ra and Rb is H; and the other is 3-methylphenyl.
Alkyl, alkenyl, alkynyl, aryl, heteroaryl (e.g., 1-oxy-pyridinyl), cyclyl, heterocyclyl mentioned above include both substituted and unsubstituted moieties. The term xe2x80x9csubstitutedxe2x80x9d refers to one or more substituents (which may be the same or different), each replacing a hydrogen atom. Examples of substituents include, but are not limited to, halogen, hydroxyl, amino, alkylamino, arylamino, dialkylamino, diarylamino, cyano, nitro, mercapto, carbonyl, carbamido, carbamyl, carboxyl, thioureido, thiocyanato, sulfoamido, C1xcx9cC6 alkyl, C1xcx9cC6 alkenyl, C1xcx9cC6 alkoxy, aryl, heteroaryl, cyclyl, heterocyclyl, wherein alkyl, alkenyl, alkoxy, aryl, heteroaryl cyclyl, and heterocyclyl are optionally substituted with C1xcx9cC6 alkyl, aryl, heteroaryl, halogen, hydroxyl, amino, mercapto, cyano, or nitro. The term xe2x80x9carylxe2x80x9d refers to a hydrocarbon ring system having at least one aromatic ring. Examples of aryl moieties include, but are not limited to, phenyl, naphthyl, and pyrenyl. The term xe2x80x9cheteroarylxe2x80x9d refers to a hydrocarbon ring system having at least one aromatic ring which contains at least one heteroatom such as O, N, or S. Examples of heteroaryl moieties include, but are not limited to, furyl, pyrrolyl, thienyl, oxazolyl, imidazolyl, thiazolyl, pyridinyl, pyrimidinyl, quinazolinyl, and indolyl. The terms xe2x80x9ccyclylxe2x80x9d and xe2x80x9cheterocyclylxe2x80x9d refer to partially and fully saturated mono- or bi-cyclic rings having from 4 to 14 ring atoms. A heterocyclyl ring contains one or more heteroatoms (e.g., O, N, or S). Exemplary cyclyl and heterocyclyl rings are cycylohexane, piperidine, piperazine, morpholine, thiomorpholine, and 1,4-oxazepane.
Below is an exemplary compound of this invention: 
In another aspect, this invention features a pharmaceutical composition that contains a pharmaceutically acceptable carrier and an effective amount of at least one of the pyrimidine compounds of this invention.
In further another aspect, the present invention features a method for treating an IL-12 overproduction-related disorder (e.g., rheumatoid arthritis, sepsis, Crohn""s disease, multiple sclerosis, psoriasis, or insulin-dependent diabetes mellitus). The method includes administering to a subject in need thereof an effective amount of one or more pyrimidine compounds of this invention.
The pyrimidine compounds of this invention include the compounds themselves, as well as their salts and their prodrugs, if applicable. Such salts, for example, can be formed between a positively charged substituent (e.g., amino) on a compound and an anion. Suitable anions include, but are not limited to, chloride, bromide, iodide, sulfate, nitrate, phosphate, citrate, methanesulfonate, trifluoroacetate, and acetate. Likewise, a negatively charged substituent (e.g., carboxylate) on a compound can form a salt with a cation. Suitable cations include, but are not limited to, sodium ion, potassium ion, magnesium ion, calcium ion, and an ammonium cation such as teteramethylammonium ion. Examples of prodrugs include esters and other pharmaceutically acceptable derivatives, which, upon administration to a subject, are capable of providing the pyrimidine compounds described above.
In addition, some of the pyrimidine compounds of this invention have one or more double bonds, or one or more asymmetric centers. Such compounds can occur as racemates, racemic mixtures, single enantiomers, individual diastereomers, diastereomeric mixtures, and cis- or trans- or E- or Z-double isomeric forms.
Also within the scope of this invention are a composition containing one or more of the compounds described above for use in treating an IL-12 overproduction-related disorder, and the use of such a composition for the manufacture of a medicament for the just-described use.
Other features, objects, and advantages of the invention will be apparent from the description and from the claims.
The compounds described above can be prepared by methods well known in the art, as well as by the synthetic routes disclosed herein. For example, a pyrimidine compound can be prepared by using 2,4,6-trichloro-pyrimidine as a starting material. The three chloro groups can be displaced by various substitutes. More specifically, first chloro group (e.g., at position 6) can react with, e.g., morpholine, to form a morpholinyl pyrimidine. 2-Aryl and 2-alkylpyrimidinde dichloro compounds can also be prepared by reacting an amidine with a malonic ester followed by treatment with phosphorous oxychloride. Second chloro group can be replaced by reacting with a nucleophile, such as an alcohol in the presence of base, e.g., sodium hydride. Isomeric forms may be produced. The desired isomeric product can be separated from others by, e.g., high performance liquid chromatography. Third chloro group undergoes a displacement reaction with, e.g., hydrazine, and the primary amine of the coupled hydrazine moiety further reacts with an aldehyde. Thus, a pyrimidine compound of this invention is obtained.
The chemicals used in the above-described synthetic routes may include, for example, solvents, reagents, catalysts, and protecting group and deprotecting group reagents. The methods described above may also additionally include steps, either before or after the steps described specifically herein, to add or remove suitable protecting groups in order to ultimately allow synthesis of the pyrimidine compounds. In addition, various synthetic steps may be performed in an alternate sequence or order to give the desired compounds. Synthetic chemistry transformations and protecting group methodologies (protection and deprotection) useful in synthesizing applicable pyrimidine compounds are known in the art and include, for example, those described in R. Larock, Comprehensive Organic Transformations, VCH Publishers (1989); T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 2nd Ed., John Wiley and Sons (1991); L. Fieser and M. Fieser, Fieser and Fieser""s Reagents for Organic Synthesis, John Wiley and Sons (1994); and L. Paquette, ed., Encyclopedia of Reagents for Organic Synthesis, John Wiley and Sons (1995) and subsequent editions thereof.
A pyrimidine compound thus obtained can be further purified by flash column chromatography, high performance liquid chromatography, or crystallization.
Also within the scope of this invention is a pharmaceutical composition that contains an effective amount of one or more of the pyrimidine compounds of this invention and a pharmaceutically acceptable carrier. Further, the present invention covers a method of administering an effective amount of such a compound to a subject in need of treatment of IL-12 overproduction related diseases (e.g., rheumatoid arthritis, sepsis, Crohn""s disease, multiple sclerosis, psoriasis, or insulin-dependent diabetes mellitus). xe2x80x9cAn effective amountxe2x80x9d refers to the amount of the compound which is required to confer a therapeutic effect on the treated subject. The interrelationship of dosages for animals and humans (based on milligrams per meter squared of body surface) is described in Freireich et al., (1966) Cancer Chemother Rep 50: 219. Body surface area may be approximately determined from height and weight of the patient. See, e.g., Scientific Tables, Geigy Pharmaceuticals, Ardley, N.Y., 1970, 537. An effective amount of the pyrimidine compound of this invention can range from about 0.001 mg/Kg to about 1000 mg/Kg. Effective doses will also vary, as recognized by those skilled in the art, depending on the diseases treated, route of administration, excipient usage, and the possibility of co-usage with other therapeutic treatments such as use of other agents.
To practice the method of the present invention, a pyrimidine compound, as a component of a pharmaceutical composition, can be administered orally, parenterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally or via an implanted reservoir. The term xe2x80x9cparenteralxe2x80x9d as used herein includes subcutaneous, intracutaneous, intravenous, intramuscular, intraarticular, intraarterial, intrasynovial, intrasternal, intrathecal, intralesional and intracranial injection or infusion techniques.
A sterile injectable composition, for example, a sterile injectable aqueous or oleaginous suspension, can be formulated according to techniques known in the art using suitable dispersing or wetting agents (such as, for example, Tween 80) and suspending agents. The sterile injectable preparation can also be a sterile injectable solution or suspension in a non-toxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that can be employed are mannitol, water, Ringer""s solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium (e.g., synthetic mono- or diglycerides). Fatty acids, such as oleic acid and its glyceride derivatives are useful in the preparation of injectables, as are natural pharmaceutically-acceptable oils, such as olive oil or castor oil, especially in their polyoxyethylated versions. These oil solutions or suspensions can also contain a long-chain alcohol diluent or dispersant, or carboxymethyl cellulose or similar dispersing agents. Other commonly used surfactants such as Tweens or Spans or other similar emulsifying agents or bioavailability enhancers which are commonly used in the manufacture of pharmaceutically acceptable solid, liquid, or other dosage forms can also be used for the purposes of formulation.
A composition for oral administration can be any orally acceptable dosage form including, but not limited to, capsules, tablets, emulsions and aqueous suspensions, dispersions and solutions. In the case of tablets for oral use, carriers which are commonly used include lactose and corn starch. Lubricating agents, such as magnesium stearate, are also typically added. For oral administration in a capsule form, useful diluents include lactose and dried corn starch. When aqueous suspensions or emulsions are administered orally, the active ingredient can be suspended or dissolved in an oily phase combined with emulsifying or suspending agents. If desired, certain sweetening, flavoring, or coloring agents can be added. A nasal aerosol or inhalation composition can be prepared according to techniques well-known in the art of pharmaceutical formulation and can be prepared as solutions in saline, employing benzyl alcohol or other suitable preservatives, absorption promoters to enhance bioavailability, fluorocarbons, and/or other solubilizing or dispersing agents known in the art. A pyrimidine compound of this invention can also be administered in the form of suppositories for rectal administration.
The carrier in the pharmaceutical composition must be xe2x80x9cacceptablexe2x80x9d in the sense of being compatible with the active ingredient of the formulation (and preferably, capable of stabilizing it) and not deleterious to the subject to be treated. For example, solubilizing agents such as cyclodextrins, which form specific, more soluble complexes with the compounds of this invention, or one or more solubilizing agents, can be utilized as pharmaceutical excipients for delivery of the pyrimidine compounds. Examples of other carriers include colloidal silicon dioxide, magnesium stearate, cellulose, sodium lauryl sulfate, and DandC Yellow #10.
The biological activities of a pyrimidine compound can be evaluated by a number of cell-based assays. One of such assays can be conducted using cells from human peripheral blood mononuclear cells (PBMC) or human monocytic cell line (THP-1). The cells are stimulated with a combination of human interferon-xcex3 (IFNxcex3) and lipopolysaccharide or a combination of IFNxcex3 and Staphylococcus aureus Cowan I in the presence of a test compound. The level of inhibition of IL-12 production can be measured by determining the amount of p70 by using a sandwich ELISA assay with anti-human IL-12 antibodies. IC50 of the test compound can then be determined. Specifically, PBMC or THP-1 cells are incubated with the test compound. Cell viability was assessed using the bioreduction of MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] (Promega, Madison, Wis.).
A pyrimidine compound can also be evaluated by animal studies. For example, one of such studies involves the ability of a test compound to treat adjuvant arthritis (i.e., a IL-12 overproduction related disorder) in rats.